Polyglycol-polyacid ester treatment of textiles



United States Patent POLYGLYCOL-POLYACID ESTER TREATMENT OF TEXTILES No Drawing. Application June 20, 1955 Serial No. 516,755

22 Claims. c1. 117 1ss.s

This invention relates to the treatment of textile fibers of all varieties with the esters of polyalkylene glycols or their monoesters or monoethers with certain polyacids and to the resulting impregnated textile articles.

An object of the invention is to provide fibrous textile materials of improved strength or resistance to wear.

Another object of the invention is to provide a treatment which enhances the strength or wearing qualities of fibrous textile materials.

Other objects and advantages of the present invention will be apparent to those skilled in the art from the detailed disclosure hereinbelow.

The present invention is concerned with fibrous textile materials impregnated with one or more esters of a polymerized aliphatic monohydroxy monocarboxylic acid with an alcohol of the group consisting of polyalkylene glycols, monoesters thereof, and monoethers thereof, as Well as with the impregnating process. Narrower aspects of the invention involve the preferred types of esters, the preferred constituents thereof, and those fibers which are susceptible to outstanding improvement.

The novel compounds comprise esters or ether-esters of high molecular weights ranging from about 400 to about 225,000 containing a polyoxyalkylene chain having a molecular weight between about 200 and about 25,000 with a polyacid residue chain or chains with molecular weights totalling between about 200 and about 200,000 attached at one or at both ends of the polyoxyalkylene chain. This group of compounds is probably best illustrated by the following formula:

where R is of the group consisting of hydrogen and alkyl radicals; R is of the group consisting of hydrogen, aryl, and lower alkyl radicals; A is of the group consisting of hydroxyl, alkoxy, cycloalkoxy, aralkoxy, araloxy, monoacyloxy and radicals; x is 0 or a positive integer, y is an integer greater than 1 and z is an integer greater than 2. It will, of course, be realized that the values of x, y, and z are only whole numbers in the case of an individual compound and that mixtures are usually involved in which these values are expressed in decimals which represent the average values for the various proportions of individual compounds present in the mixture. When in the above formula A represents a hydroxyl group, the compound is a monoestenwhen it is a ice radical the compound is a diester; when A designates a monoacyloxy group, the compound is a mixed ester; and when A stands for an oxygenated hydrocarbon radical, such as an alkoxy group, the compound is a monoether-monoester. It is to be emphasized that the polyoxyalkylene chain is'not interrupted by carboxylic acid residues but that the latter form either one or two also uninterrupted chains which are attached at one or both ends of the polyoxyalkylene radical.

In preparing the compounds used in the present invention, a wide variety of monohydroxy monocarboxylic aliphatic acids or their anhydrides, lactones, lactides or esters may be employed; and the position of the single hydroxyl radical on the carbon chain of the acid is not important. Thus, a wide variety of alpha, beta, gamma, delta, etc., hydroxy-substituted acids or derivatives is suitable, including glycolic, lactic, B-hydroxypropionic (hydracrylic), a-hydroxyisobutyric, ,B-hydroxyisobutyric, a-hydroxybutyric, B-hydroxybutyric, a-hydroxyvaleric, ahydroxycaproic, a-hydroxyisovaleric, hydroxypivalic, l2- hydroxyoctadecanoic, lactyllactic, and w-hydroxypalmitic acids; ethyl lactate, lactide, e-caprolactone, -stearolactone, fi-propionolactone, -butyrolactone, o-valerolactone, and the lactone of w-hydroxypentadecanoic acid. The condensation polymers formed from these monomeric acids may be substituted as reactants and such a polyacid must be employed when a monoester of a polyacid and a polyalkylene glycol is produced unless there is an ether or ester group already blocking one end of the polyglycol. Polyhydroxy acids are not equivalents of monohydroxy acids of the type indicated, inasmuch as the polyhydroxy acids tend to cross-link; and cross-linking appears undesirable for the present purposes.

The expression ester in connection with various acids is used broadly herein to indicate the acid and other residues present in the product esters and not their source; that is, not to limit the products to any method of preparation or reactants employed therein. For example, an ester of a polymerized lactic acid and a polyethylene glycol is intended to include esters prepared from monomeric lactic acid, monomeric ethyl lactate, polymerized methyl lactate, lactide, lactones or polylactic acid, as well as any other reactants capable of forming a polylactic acid residue or radical in the ester.

Of the polyalkylene glycols, polyethylene glycol is greatly preferred due to its low cost and ready availability and especially where the higher molecular weight water-soluble esters are concerned. However, in the type formula given above, each R substituent of the polyoxyalkylene residue may be a l to 4 carbon alkyl group such as methyl, ethyl, propyl, and isopropyl or the various normal and isomeric butyl groups, as well as a phenyl radical or hydrogen. Among the many other useful polyglycols are polypropylene glycol, 1,2-polybutylene glycol, 2,3-polybutylene gycol, polyisobutylene glycol, and polyphenylethylene glycol.

Monoethers of the same polyalkylene glycols may be used in lieu of the polyalkylene glycol reactant. The resulting products in this case are ether-esters. A wide variety of the ethers are operative as reactants, as for instance, alkyl ethers, cycloalkyl ethers, aralkyl ethers and aryl ethers of the polyalkylene glycols. Among the myriad of these ethers, a few illustrative species include methoxypolyethylene glycol, butoxypolypropylene glycol and ethers having a single propoxy isobutoxy, lauryloxy, phenoxy, benzyloxy, phenylethoxy, stearyloxy, naphthoxy, p-chlorophenoxy, t-octylphenoxy, etc., group replae ing the hydroxyl group at one end of a polyethylene, polypropylene, polybutylene, polyisobutylene, and polyphenylethylene glycol chain.

Other suitable agents are a group of mixed esters of the polyalkyleue glycols; that is esters containing a polyacid residue at one end of the polyoxyalkylene chain and a monoacyloxy radical or residue of a monomeric monocarboxylic acid free of hydroxyl groups other than the carboxylic hydroxyl radical at the other end. The latter acid may be any organic non-hydroxylated monocarboxylic acid of aliphatic, aromatic, or mixed varieties including formic, acetic, propionic, butyric, caprylic, caproic, lauric, palmitic, stearic, cerotic, palrnitoleic, oleic, linoleic, cetoleic, benzo-ic, (o-, m-, and p-) toluic, m-, and p-) chlorobenzoic, (0-, m-, and p-) nitrobenzoic, anisic, phenylacetic, hydrocinnamic, e-phenyl-n-caproic, phenylpropiolic acids and the like. The mixed esters may be prepared by simultaneously treating the polyglycol with a mixture of both esterifying acids. However, to reduce the quantity of by-product esters, it is recommended that the glycol be esterified with a single acid in suitable proportions to direct the reaction toward the formation of a monoester, and that the polyalkylene glycol monoester then be reacted with the other acid to produce the mixed ester.

The preparation of such agents is quite simple, as it merely involves heating the reactants in the presence of an acidic catalyst capable of reducing the pH of the mixture below about 5 (e.g., phosphoric or sulfuric acid) at a temperature sufliciently elevated to produce condensation of the reactants by splitting off water. The water should be separated from the reaction mass to avoid setting up an equilibrium with the reverse hydrolysis reaction. A conventional entraining agent such as ben zene, xylene, toluene, and other hydrocarbons of suitable volatility is desirable to facilitate removal of the water. Refiuxing of the reactants under atmospheric pressures at reflux temperatures in the range between about 60 and about 190 C. is recommended. As the reaction proceeds, the reflux temperature rises slowly over a lengthy period and water is withdrawn from a conventional trap in the reflux condenser. Completion of the reaction is easily determined by comparing the Water collected with the theoretical yield of water making due allowance for any water introduced with the reactants. These novel esters and their preparation are described in detail and claimed in the concurrently filed application Serial No. 516,757 of Frank M. Cowen, now abandoned.

The application of the ester to textile materials in the form of yarns, threads, or fabrics of the woven, oriented nonwoven, felted, or knitted variety is easily accomplished by various means including sprays and baths. If desired, these esters may be applied without dilution by simply heating the ester moderately to melt it or reduce its viscosity. However, for most purposes, more uniform distribution and better control of the quantity deposited on the fibrous material is obtained by application of a dispersion or solution of the ester in water or another suitable solvent including ethanol, isopropanol, ethylene glycol, acetone, benzene, butanol, dioxane and cyclohexanol, or from a water emulsion with mineral oil.

Aqueous solutions of the esters and self-dispersible esters are, of course, preferred for simplicity; but waterinsoluble esters of the nature described may be suitably dispersed in water with a conventional surface active agent such as sodium lauryl sulfate, dioctyl sodium sulfosuccinate, tertiary octyl phenol-ethylene oxide condensate, sodium stearate or dodecyl benzene sodium sulfonate. The concentration of ester in such solutions or dispersions may range from about 0.2 to 40%, and the range between 0.5 and is usually preferred. Any liquid medium selected as a vehicle for distributing the esters should, of course, be one which does not completely dissolve any of the fibers or blend thereof in the yarns or fabrics undergoing treatment. The quantity of the agent deposited on the fibrous material may be controlled in .the usual manner by adjustment of the concentration of ester in the liquid medium and the pressure on the squeeze rolls through which the wet impregnated material is passed. The impregnated material is then dried at any temperature ranging from atmospheric temperatures up to a point just below the temperature at which decomposition of either the fibers or the ester commences, 150 to 300 F. being recommended for commercial operations. A dry pickup or add-on of about 0.2 to about 40%, 0.5 to 15% being preferred, of the active agent based on the dry weight of untreated fibers is recommended for most purposes.

The treatment of the present invention has been found to provide a lubricating or softening effect on certain fibers; for example, viscose rayon. Therefore, it has distinct utility as an agent for minimizing damage to yarns during spinning, weaving and knitting either alone or in conjunction with other textile oils and softeners. For most purposes, it is desirable to apply the ester in the last bath to which a woven or knitted fabric is subjected in a finishing plant. It is especially contemplated that the agents of this invention may be applied after or in combination with other textile finishes, particularly those with a tendency to tender or lower the tear strength of the various fabrics.

Although the effect of the present treatment on textile materials is not completely understood, it is believed to provide a simple physical coating on the exterior of the individual filaments of the textile materials because there is no exotherm or other evidence of a chemical reaction between the fibers and the esters described herein. This is borne out by the fact that improvement, although often of varying extent, has been obtained in respect to at least some characteristics on all types of fibers, including vegetable fibers, protein fibers, and several classes of synthetic and artificial fibers. Accordingly, the invention is applicable to the treatment of cotton, cyanoethylated cotton, flax, ramie, hemp, manila, silk, wool, mohair, linear superpolyamides, as exemplified by nylon of both the adipamide and caprolactam types, acrylic fibers in general, and especially acrylonitrile polymers including homopolymers and copolymers with vinyl acetate, methyl acrylate, 2- methyl-S-vinyl pyridine, and other vinyl pyridines etc., cellulose acetate, including cellulose triacetate, viscose rayon, cuprammonium rayon, vinyl chloride, vinylidine chloride copolymers, casein and polyester fibers such as polyethylene glycol terephthalate, as well as blends of any of these. Since the effects appear to result from the formation of a partial or continuous film of the ester on individual filaments, it is hardly surprising that the present treatment is operative with all known fibers suitable for use in textiles.

All of the effects described herein are peculiar to the esters described above, inasmuch as the ammonium and sodium polylactates and polylactic acid itself in the same molecular weight range are found to produce only a minor improvement of the type described herein in comparison with the aforesaid esters.

For a better understanding of the nature and objects of the present invention, reference should be had to the following illustrative examples in which all proportions are set forth in terms of weight unless otherwise specified therein.

EXAMPLES l9 HO[ CH0 0 0 Woven fabrics of the types listed below are each passed through an aqueous solution maintained at to Table I EFFECT OF 2.5% PEG/PLA 3/1 RATIO ON TEAR AND ABRASION Stoll Flex Abrasion (Cycles I Elmendorf Tear Strength (lbs) Ex. Cloth Treated Treated Treated Control Rayon Suiting Wool Cotton Poplin Cotton Percale 1 A registered trademark of E. I. du Pont de Nemours and Compan for a copolymcr yam of 94% acrylonitrile and 6% methylacrylate.

2 A registered trademark of E. I. du Pont de Nemours and Company for a polyethylene glycol terephthalate yarn.

3 A registered trademark of Union Carbide and Carbon Corporation for a copoiymer yarn 01' 60% vinyl acetate and 40% acrylonitrile.

Trapezoid tear strength tests run on the Instron tensile, tear, elongation and recovery combination tester confirm the Elmendorf test data. In addition, certain fabrics display a smaller but nevertheless very substantial increase in tensile strength amounting to 9.2% for the Dacron, 13.7% for cellulose acetate, and 18.2% for the rayon suiting.

Cotton, viscose rayon, and nylon tire cords are impregnated with a sufficient quantity of the ester solution to provide an add-on of 2.5% by weight and also with mixtures thereof with a water-soluble resorcinol resin prepared by condensing 8.7 parts by weight of 37% aqueous formaldehyde with 4 parts of resorcinol, with a natural rubber latex, and with a mixture of both. The impregnated cords are dried for 5 minutes at 85 C. and then imbedded in the surface of a natural rubber carcass stock which is cured for 45 minutes at 138 C. Upon measuring the force required to pull the various cords in pairs from the carcass stock at a rate of 2 inches per minute, it is found that the ester employed in the present invention has no appreciable deleterious effect on the adhesion of tire cords to rubber.

EXAMPLES 10-18 Samples of the same rayon challis are impregnated to a dry pickup of 2.5% with each of a series of esters according to the procedure described for Examples l9. These esters are prepared by condensing a polyethylene glycol of 6750 molecular weight with differing amounts of lactic acid.

Table II Stoll Flex Elmendorf Examples PEG/PLA Abra ion, Tear Ratio Cycles Strength (lbs) Control 1, 320 5. 1. 10:1 9.0 1.15:1 1,825 8. 1. 2:1 1, 950 9.1 1. 4:1 2.110 0. 5 1. 6:1 2, 260 10. 5 2.021 2,780 1L5 3. 0:1 3. 480 15.0 4. 0:1 3.100 16.0 5. 0:1 2, 600 15. 5

It is noted that the maximum abrasion resistance is obtained with a PEG/PLA ratio of about 3:' 1 and that the maximum tear strength is reached at a ratio of about 4:1. While all ratios produce very substantial improvement over the untreated control material, nevertheless PEG/PLA ratios in the ester extending from about 1.5:1 to about 6:1 are considered to provide the optimum effects on textile fibers in general.

EXAMPLE 19 An ester with an average molecular weight of 5105 and a PEG/polyglycolic acid ratio of 1.87:1 is obtained by condensing 92 parts of glycolic acid with 134 parts of a polyethylene glycol mixture with an average molecular weight of 3350. A 10% aqueous solution of this agent is applied to the same viscose rayon suiting fabric in sufiicient quantity and dried thereon to provide a dry pickup of 10% by weight.- The treated fabric shows a very distinct improvement over that of an untreated swatch of material in both tear strength and abrasion resistance.

* EXAMPLE 20 A monoether-monoester is prepared by reacting 1.63 mols of lactic acid and 0.2 mol of methoxy polyethylene glycol having an average molecular weight of 750. This material has an average molecular weight of 1336 and a PEG/PLA ratio of 1.2: 1. A 5% dry pickup of this ester on the same viscose suiting fabric is produced by application from an aqueous medium followed by the usual drying. Again, a sharp increase in the tear strength of the treated fabric is noted in comparison with that of the untreated material.

EXAMPLES 2136 The procedure employed in the first group of examples is duplicated in impregnating pieces of the same viscose rayon challis witha 2.5 add-on of various diesters of the following approximate general formula:

HO-[CHOOO] OH2OH20 )rlCH2CH2[OOO(fH] OH CH3 n CH3 '/L For comparison, the tensile and tear strengths obtained with the treated fabrics are listed below along with those of the untreated rayon and a sample impregnated with 2.5 by weight of a polylactic acid.

Table III Suter Grab Elmendorf Example '11, a: Test, Tensile Tear Strength Strength (165.) (lbs.)

Untreated 126 4. 2 49. 0 Polylactie 126 4. 5

acid. 3. 4 34. 0 137 6.0 6. 6 12.2 139 8. 4 8.0 12. 2 139 7. 2 9. 2 12. 2 138 7. 1 12.6 13. 6 138 7. 4 13. 4 22. 3 146 7. 9 14. 4 13. 6 136 6. 2 16. 4 16. 3 136 7. 5 19. 6 32. 5 138 8. 3 37. 8 74. 8 147 7. 7 45. 4 74.8 144 7. 9 53. 0 74. 8 141 7. 4 76. 6 152. 0 141 7. 7 91. 8 152.0 141 7. 7 107. 0 152. 0 147 7. 2 3. 3 1 6. 6 7. 2

1 Polypropylene glycol analog.

While there are above disclosed a number of illustrative embodiments of the articles and process of the present invention, it is to be understood that these are not intended for purposes of limitation, inasmuch as there are many variations and modifications which fall within the scope of the present invention. It is desired, therefore, that only such limitations be imposed upon the appended 7 claims as are stated therein or required by the prior art.

What I claim is:

1. An article which comprises a fibrous textile material having improved abrasion resistance and tear strength impregnated with an ester of a polymerized aliphatic monohydroxy monocarboxylic acid with an alcohol of the group consisting of polyalkylene glycols, monoesters thereof, and monoethers thereof.

2. An article according to claim 1 in which the acid comprises lactic acid.

3. An article according to claim 1 in which the alcohol comprises a polyethylene glycol.

4. An article which comprises a fibrous textile material having improved abrasion resistance and tear strength impregnated with a diester of a polymerized aliphatic monohydroxy monocarboxylic acid with a polyalkylene glycol.

5. An article which comprises a fibroustextile material having improved abrasion resistance and tear strength impregnated with a diester of a polymerized lactic acid and a polyethylene glycol.

6. An article which comprises a fibrous textile material having improved abrasion resistance and tear strength impregnated with a diester of .a polymerized lactic acid and a polypropylene glycol.

7. An article which comprises a fibrous textile material having improved abrasion resistance and tear strength impregnated with a diester of a polymerized glycolic acid and a polyethylene glycol.

8. An article which comprises a fibrous textile material having improved abrasion resistance and tear strength impregnated with an ether-ester of a polymerized aliphatic monohydroxy monocarboxylic acid with a polyethylene glycol monoalkyl ether.

9. An article which comprises a textile material having improved abrasion resistance and tear strength containing fibers of the group consisting of cellulose, nylon, cellulose acetate, polyethylene glycol terephthalate and acrylonitrile polymer fibers impregnated with between 0.2 and 40 percent based on the dry untreated fibers weight of an ester of a polymerized aliphatic monohydroxy monocarboxylic acid with an alcohol of the group consisting of polyalkylene glycols, monoesters thereof, and monoethers thereof, the average ratio of the polyalkylene .glycol content to the polyacid content of which ester is between about 1.5 :1 and 6.0:1.

10. An article which comprises a textile material having improved abrasion resistance and tear strength containing fibers of the group consisting of cellulose, nylon, cellulose acetate, polyethylene glycol terephthalate, and acrylonitrile polymer fibers impregnated with between about 0.2 and about 40 percent based on the dry untreated fibers weight of an ester of a polymerized lactic acid with an alcohol of the group consisting of polyalkylene glycols, monoesters thereof,,and monoethers thereof.

11. An article which comprises a textile material having improved abrasion resistance and tear strength .containing fibers of the group consisting of cellulose, nylon, cellulose acetate, polyethylene glycol terephthalate, and acrylonitrile polymer fibers impregnated with between about 0.2 and about 40 percent based onfthe dryuntreated fibers weight of an ester of a polymerized aliphatic nlronohydroxy monocarboxylic acid with a polyethylene g ycol.

12. An article which comprises a textile materialhaving improved abrasion resistance and tear strength containing viscose rayon fibers impregnated with between about 0.5 and about percent based on the dry untreated fibers weight of a diester of a polymerized lactic acid and a polyethylene glycol in which the average ratio of the polyethylene glycol content to the' polylactic acid content is between about 1.521 and about 6.0:1.

'13. An article .which comprisesa' textile material hav- ,mg improvedabrasion resistance and tear strength con- :taining cellulose acetate fibers impregnated with between 8 about 0.5 and about 15 percent based on the dry untreated fibers weight of a diester of a polymerized lactic acid and a polyethylene glycol in which the average ratio of the polyethylene glycol content to the polylactic acid content is between about 1.5:] and about 6.0:l.

14. An article which comprises a textile material having improved abrasion resistance and tear strength containing polyethylene glycol terephthalate fibers impregnated with between about 0.5 and about 15 percent based on the dry untreated fibers weight of a diester of a polymerized lactic acid and a polyethylene glycol in which the average ratio of the polyethylene glycol content to the polylactic acid content is between about 1.5:1 and about 6.0:1.

15. A process which comprises impregnating a fibrous textile material with a dispersion of an ester of a polymerized aliphatic monohydroxy monocarboxylic acid with an alcohol of the group consisting of polyalkylene glycols, monoesters thereof, and monoethers thereof, and drying the impregnated material to deposit said ester thereon, whereby a textile material of improved abrasion resistance and tear strength is provided.

16. A process which comprises impregnating a fibrous textile material with a dispersion of a diester of a polymerized aliphatic monohydroxy monocarboxylic acid with a polyalkylene glycol, and drying the impregnated material to deposit the ester thereon, whereby a textile material of improved abrasion resistance and tear strength is provided.

17. A process which comprises impregnating a fibrous textile material with a dispersion of an ester of a polymerized lactic acid with an alcohol of the group consisting of polyalkylene glycols, monoesters thereof, and monoethers thereof, and drying the impregnated material to deposit said ester thereon, whereby a textile material of improved abrasion resistance and tear strength is provided.

18. A process which comprises impregnating a fibrous textile material with a dispersion of an ester of a polymerized aliphatic monohydroxy monocarboxylic acid with a polyethylene glycol, and drying the impregnated material to deposit the ester thereon, whereby atextile material of improved abrasion resistance and tear strength is provided.

19. A process which comprises impregnating a fibrous textile material with a dispersion of a diester of a polymerized lactic acid and a polyethylene glycol, and drying the impregnated material to deposit the ester thereon, whereby a textile material of improved abrasion resistance and tear strength is provided.

20. A process which comprises impregnating a textile material containing fibers of the group consisting of cellulose, nylon, cellulose acetate, polyethylene glycol terephalate and acrylonitrile polymer fibers with an aqueous dispersion of an ester of a polymerized lactic acid with an alcohol of the group consisting of polyalkylene glycols, monoesters thereof, and monoethers thereof in sufficient quantity to provide a pickup of between about 0.2 and about 40 percent of said ester based on the dry untreated fibers weight and drying the impregnated material to deposit the ester thereon, whereby a textile material of improved abrasion resistance and tear strength is provided.

21. A process which comprises impregnating a textile material containing fibers of the group consisting of cellulose, nylon, cellulose acetate, polyethylene glycol terephthalate and acrylonitrile polymer fibers with an aqueous "dispersion of a suflicient quantity of an ester of a polymerized aliphatic monohydroxy monocarboxylic acid with a polyethylene glycol to provide a pickup of between about 0.2 and about 40 percent of the ester based on the dry untreated fibers weight and drying the impregnated material to deposit the ester thereon, whereby a -textile material of improved abrasion resistance andtearstrength is provided.

22. A process which comprises impregnating a textile 9 10' 7 material containing viscose rayon fibers with a suflicient 2,078,239 Ellis Apr. 27, 1937 quantity of an aqueous solution of a diester of a poly- 2,120 75 Kyrides Ju 14, 1938 merized lactic acid and a polyethylene glycol .to provide 2 151 185 camlthers Mar 21 1939 a pickup between about 0.5 and about 15 percent of the ester based on the dry untreated fibers weight and drying 5 the impregnated material to deposit the ester thereon, FOREIGN PATENTS whereby a textile material of improved abrasion resistance and tear strength is provided, the average ratio of 24254 Great f f 1913 the polyethylene glycol content to the polyactic acid con- 508,016 Great Bntam June 21, 1939 tent in the ester being between about 1.5 and about 6.0. 10 698,616 Germany Nov. 14, 1940 References Cited 1n the file of th1s patent OTHER REFERENCES UNITED STATES PATENTS Steam (Industrial and Engineering Chemistry, vol. 32, Re. 23,866 Bricks Sept. 14, 1954 15 N0. 10), October 1940, pp. 1335 to 1342 relied on). 

